Adapt code to use G4AtlasActionInitialization

Here we adapt the various clients of the `UserActionSvc` to create
(in the case of `G4AtlasAlg`, `G4LegacyTransportTool` and
`G4TransportTool`) `G4AtlasActionInitialization` or use it
(`G4AtlasRunManager`, `G4AtlasUserWorkerThreadInitialization`,
`G4AtlasWorkerRunManager`).